UNIVERSITY OF NATAL, SOUTH AFRICA
Optimising the feeding of commercial broilers during their growing period is made difficult because of the many interacting factors influencing the growth and food intake of these birds. Not all broilers are the same, nor are the environments in which they are housed, and the costs of feeding and the revenue derived from the sale of the product differs markedly from one locality to another. When making decisions about how to maximise some economic index, such as margin/m2 annum or breast meat yield in a commercial broiler operation, all of these interacting factors should be considered simultaneously. This is now possible, using optimisation techniques, but only if food intake can be accurately predicted.
The basis of such an optimisation process is that the optimiser passes suggested feeds or feeding schedules to a feed formulation program, which produces a least-cost feed and passes this on to a broiler growth model that, in turn, evaluates the suggested feeding programme. By following certain rules the optimiser continues to alter the specifications for the feeds and/or feeding programme until no improvement can be made in the objective function. Without an accurate prediction of the amount of food that a given broiler will consume in the given environment, such an optimisation process is bound to fail. The broiler growth model described here predicts food intake accurately under most circumstances that would be experienced in a commercial broiler operation, making it possible now to optimise the feeding programme of commercial broilers under a wide range of biological, environmental and economic circumstances, using many different objective functions.